Method for processing cellulose containing materials to impart thereto flame resistance

ABSTRACT

This invention relates to a new method for treating cellulosic materials to imparting flame resistance coupled with excellent fastness or resistance to washing and crease resistance. The process employs a phosphorus compound containing methylene ether bonds and a residue of a nitrogen containing compound capable of forming a dimethylol compound.

United States Patent 1191 Yamamoto 1451 Sept. 23, 1975 METHOD FOR PROCESSING CELLULOSE CONTAINING MATERIALS TO IMPART THERETO FLAME RESISTANCE Inventor: Kosuke Yamamoto, Kamakura,

Japan Mitsui Toatsu Chemicals, Incorporated, Tokyo, Japan Filed: Feb. 28, 1974 Appl. No.: 446,802

Assignee:

Foreign Application Priority Data Feb, 28, 1973 Japan 48-23266 US. Cl 427/396; 106/15 FP; 252/8.1; 260/932; 260/D1G. 24; 427/354; 427/382; 428/276; 428/921 Int. Cl. C09D 5/18 Field of Search 117/143 R, 136, 137, 147, 117/154, 118; 8/116 P; 252/8.l; 260/932; 106/15 FP; 427/354, 382, 396; 428/276, 921

[56] References Cited UNITED STATES PATENTS 3,658,952 4/1972 Nachbur et a1. 117/137 X 3,699,192 10/1972 Moretti v 117/136 X 3,754,981 8/1973 Nachbur et al.. 117/136 3,763,283 10/1973 Curgan 117/136 X Primary Examiner-Michael R. Lusignan Attorney, Agent, or Firm-Lane, Aitken, Dunner & Ziems [57] ABSTRACT 4 Claims, No Drawings METHOD FOR PROCESSING CELLULOSE FLAME RESISTANCE wherein R to R are the same or different alkyl, alkenyl or alkoxyalkyl groups which may be substituted by one or more chlorine or bromine atoms, and X is a residue 5 ofa it t d OF For imparting flame resistance to cellulose containpound. ing fibrous materials, the urea phosphate process is conventionally employed (see, for example, Japanese D ETAILED DESCRIPTION OF THE INVENTION Patent Publication No. 4950/ 1962). The cloth pro- The groups R to R in the phosphorus compounds of cessedd 12y :ef urea phosphate proctess stzffers lfrom gimp]: (I)1 are of 10 or less carbon atoms and preferamany e co or examp e, poor resis ance 0 was mg, y 0 or ess carbon atoms. Of these, those phospho- .a rough finish and a poor feel as well as a great reducrus compounds (I) wherein R to R are alkyl or halogetion in strength. nalkyl groups are preferred, of the alkyl groups methyl lA :ielatlvJely new nliaethogI for6glla gggr l irlg 8 (118- group is preferred and of the halogenalkyl groups the c ose in apanese at. o. is patent, chloroethyl group is preferred, teaches that N-methylolated phosphorus compounds bearing a methylene ether bond and obtained by con- The fntrogen comammg compounds capable of forming a dimethylol compound when used as one of the redensation of 3-d1methylphosphonopropionlc acid actants In the preparation of the phosphorus commethylolamide, followed by methylolation with a reapounds (I), include for example, dlalkylureas, cyclic gent capable of generating formaldehyde, are effective alkyleneureas such as ethyleneurea, and propyleneum processlng cellulose containing fibrous materials to rea, cyclic alkyleneurea derivatives such as dlhydroxyeimpart thereto flame resistance.

. thyleneurea, 5-hydroxypropyleneurea and dlalkoxye- The N-methylolated phosphorus compounds having thyleneurea, urones, triazones, and 4-hydroxy-5, 5-. a methylene ether bond, used in the process disclosed dimethylhexahydropyrlmldm-2-one and its alkoxy dein Japanese Pat. No. 691,726, emit a formaldehyde rlvatives. Of these ethyleneurea, propyleneurea and N, odor and tend to generate formaldehyde easily in the N -d1methylurea are preferred.

process for flameproofing cellulose containing fibrous materials, thus producing an undesirable working envl- Although not limited to the following, the prepara tion of the phosphorus compounds (I) used in accor- An oblect of the preem mventlon ls to provlde a dance with the method of the present invention may nmiel for reducmg the frma1dehde conveniently be made by one of the following methods: sociated with the flameproofing of cellulosic containing materials. It is afurther object of the present invention Th fi t m th d i a rocess wherein a dimeto impart to Such materials flame resistance Coupled thylolated nitrogen containing compound is condensed with excellent fastness to washing and crease resisi h for l 3 di th l h hono ro ionamide tancewith dehydration, in the presence of an acid catalyst Another object of the Present invention is to Provide such as p-toluenesulfonic acid. The reaction may be novel compounds to enable the above objects. represented as follows:

R O HOCH -X-CH OH PCH CH CNHCH OH (I) (l) R 0 ll ll 2 O 0 SUMMARY OF THE INVENTION The above enumerated problems are overcome by In another process a dimethylolated nitrogen comwith the present invention wherein cellulose containing taining compound and monomethylol acrylamide are fibrous materials are subjected to flame proofing treat- 5 condensed with water removal in the presence of an ment with a phosphorus compound bearing methylene acid catalyst to form a divinyl compound bearing methether bonds and a residue of a nitrogen containing ylene ether bonds. The divinyl compound is then recompound capable of forming a dimethylol compound. acted with a phosphorous acid ester in the presence of These compounds contain no N-methylol groups, and a basic catalyst such as sodium methoxide. The reacare represented by the following general formula: tions are depicted in the following operation (2).

R O OR fiCH CH CNHCH OCH X-CH OCn Nl-ICCH Cn P (I) R 0 ll I] ll OR I 2 O O O O 4 HOCH2 x ca on CH2 CHENHCHZOH (CH2 cn Nficri ocay x (I) The phosphorus compounds (I) used in the method of the present invention are characterized by the presence of methylene ether bonds and by the a residue of a nitrogen containing compound capable of forming a dimethylol compound.

It is theorized that when cellulose containing fibrous materials are treated with phosphorus compounds of formula (I), the methylene ether bonds split off and simultaneously react with the hydroxy groups of the cellulosic fiber thereby attaching to the cellulosic fibers in the form of the phosphonopropionamidomethyl ether. As a consequence in the method according to the present invention, it is unnecessary to introduce, by a special method like N-methylolation, other reactive functional groups.

The residue of the nitrogen containing compound, produced by the splitting of methylene ether bonds, provides a cross-linking reaction with the cellulosic fiber, so that the treated cloth exhibits not only flame resistance coupled with excellent fastness upon washing, but also greatly enhanced crease resistance. Since the phosphorus compounds (I) do not emit a formaldehyde odor and do not generate of formaldehyde in the course of processing, the working environment is significantly improved.

The reaction catalysts used to react the cellulose con taining materials with the phosphorus compounds of formula (I) used in are those catalysts conventional in the curing of amino resins, for example ammonium chloride, orthophosphoric acid, magnesium chloride, zinc nitrate or zinc borofluoride.

The concentration in the processing solution of the phosphorus compound (I) used, for wetting the cellulosic fibrous materials may be varied in accordance with the desired degree of flame resistance to be imparted, although it will generally be within the range of from 5 to 80 percent by weight, and preferably in the range of from to 50 percent by weight.

The above described processing solutions may be applied to the cellulose containing material, by any of a variety of known methods, such as pressing between rolls, spraying or centrifugation. Likewise, the manner of drying the wetted or impregnated material is conventional and practically any temperature between room temperature and 200C suffices. With regard to curing conditions, satisfactory results are obtainable by curing at temperatures of the order on from 120 to 200C for periods of time of from seconds to 10 minutes.

In practicing the method of the present invention, amino resins may simultaneously be applied to the material by inclusion in the treatment bath. Suitable resins include the reaction products of a variety of low molecular amino compounds with formaldehyde and the alkoxylated derivatives thereof. The amino compounds usually used as starting materials for the manufacture of amino resins include, for example, urea, melamine, thiourea, ethyleneurea, guanidine and urone.

When such amino resins are used in combination with the phosphorus compounds (I), however, the working environment deteriorates because of generation of formaldehyde. When the phosphorus compounds (I) are used alone in accordance with the method of the invention, no generation of formaldehyde takes place and therefore the working environment is not adversely affected. Accordingly the application of the phosphorus compounds (I) alone is preferred.

4 EXAMPLE 1 Into a reaction flask equipped with means for the removal of reaction and a stirrer are changed 225 g (1.0 mole) monomethylolated methylethylphosphonopropionamide, 73 g (0.5 mole) freshly prepared dimethylolethyleneurea, 50 g dioxane, 200 g benzene and 1.5 g p-toluenesulfonic acid. The mixture is heated to the boiling point of the benzene, the water formed in the course of the condensation reaction is azeotropically removed and collected in the water separator. Approximately 10 hours after initiating the reaction water formation ceases. The reaction solution is then distilled under reduced pressure to remove the solvent, thus producing 282 g of a clear viscous liquid.

This viscous liquid was found to contain 0.3 percent free formaldehyde, 1.8 percent methylol-type formaldehyde and 19.14 percent methylene ether-type formaldehyde (determined as formaldehyde after decomposition with a dilute aqueous acid solution). The analytic results show that the product is of 89.4 percent purity.

A cotton No. 40 broadcloth was treated in an aqueous solution containing a 30 percent by weight of the product produced above to which solution 0.4 percent ammonium chloride had been added, washed 5 times with a 0.2 percent aqueous detergent aqueous solution and dried. The combustion test with the processed cloth showed incombustibility and the crease resistance of the processed cloth was 287 (original cloth 17.8).

For comparison, as an example of those phosphorus compounds not bearing a residue of a nitrogen containing compound capable of forming a dimethylol compound, i.e. those phosphorus compounds (I) wherein X is absent, N, N'-oxydimethylenebis(dimethylphosphono) propionamide was synthetized and employed in the same flame proofing process as described above, whereupon the crease resistance was determined to be The measurement of the crease resistance was made in accordance with the method of A.A.T.C.C. 88A-1964 T method.

EXAMPLE 2 Flame resistance tests were conducted with a cotton twill processed with the various urea derivatives as shown in Table 1 below. The composition of each of the respective processing baths as well as the test results before and after washing are also shown in Table The processing procedure was as follows: The cloth was, after impregnation, picked up percent by weight pick up), dried at 90C for 4 minutes and cured at C for 4 minutes.

The cured cloth was subjected to 10 minutes of soaping at 40C in a 0.2 percent by weight detergent (manufactured by Kao Sekken Co., Ltd.; Trade Name ZABU) aqueous solution and then rinsed for 5 minutes with water, this procedure repeated 5 times. The finally dried cloth was used as the test cloth for after washmg.

The flame resistance test was carried out in accordance with Japanese Industrial Standards (J IS )-L-l091 Al. This test method is also referred to as the 45 microbumer method. In this method the test cloth is spread over a 25 X 15 cm frame and set in a combustion test chamber at an angle of 45. The microbumer is ignited, the cloth heated for 1 minute and the flame duration or lasting time (the length of time from the end of heating to a point where flaming of the test cloth ends) is determined. The microburner is adjusted beforehand to a flame length of 4.5 cm with the tip of the flame in contact with the test cloth. Subsequently, the

or more chlorine or bromine atoms and X is a residue of a urea derivative capable of forming, when reacted with formaldehyde, a dimethylol compound, and drying said flameproofed cellulosic materials test cloth is removed from the frame and the carbon- 5 2. The method of claim 1 wherein R R R and R ized length and area are determined. are alkyl or halogenalkyl groups of 4 or less carbon Table 1 Processing Bath by weigt) Before Washing After Washing R X Ac- NH4CI l-LJO. M Cl T-36* Carbo- Carbo- Flame Carbo- Carbo- Flame tive nized nized lasting nized nized lasting agent length area time length area time m m) CH2N 30 3 6.4 22 0 6.4 22 0 CH C=O 1 CH2N 0.5 6.6 22 0 6.8 26 0 20 3 5 6.8 23 0 7.2 25 o 2 C H 5 3 7.0 20 0 7.1 29 0 3 cic l-i 30 3 6.9 23 0 6.9 28 0 5 C4H9OC2H, 3 7.0 23 0 7.8 42 0 CH2N 6 CH: C 30 0.5 5 6.4 24 0 6.8 26 0 cH. N

HOCHN\ 7 c=o 30 0.5 6.5 22 0 6.8 28 0 HOCHN/ cH,-N 8 CHQN c=0 25 2 5 6.4 21 0 6.5 24 0 CH2N H CH3\ /CHOCH3--N 9 30 2 6.5 22 0 7.2 34 0 cm CH N o=o CH3N\ l0 3o 3 5 6.6 20 0 7.0 32 0 CH N Trade name Ulamine T 36 for 30% aqueous methoxymethylolmelamine solution manufactured by Mitsui Toatsu Chemical Co., Ltd.

1 claim:

1. A method for flameproofing cellulosic materials comprising applying to the cellulosic material an aqueous solution of a phosphorus compound represented by the following general formula:

CH CH CHNCH OCH -XCH OCH CH fi 2 2 2 2 NHCCH 4. The method of claim 2 wherein R R R and R are chloroethyl groups and X is ethyleneurea.

5 wherein R to R are the same or different alkyl, alkenyl or alkoxyalkyl groups which may be substituted by one 

1. A METHOD FOR FLAMEPROOFING CELLULOSIC MATERIALS COMPRISING APPLYING TO THE CELLULOSIC MATERIAL AN AQUEOUS SOLUTION OF A PHOSPHORUS COMPOUND REPRESENTED BY THE FOLLOWING GENERAL FORMULA:
 2. The method of claim 1 wherein R1, R2, R3 and R4 are alkyl or halogenalkyl groups of 4 or less carbon atoms and X is ethyleneurea, propleneurea or N, N''-dimethylurea.
 3. The method of claim 2 wherEin R1, R2, R3 and R4 are methyl groups and X is ethyleneurea.
 4. The method of claim 2 wherein R1, R2, R3 and R4 are chloroethyl groups and X is ethyleneurea. 